Key cutting apparatus



HOFFMAN KEY CUTTINGAPPARATUS M, s m.\.

i U a Nov. 12, 1957 H. HOFFMAN KEY CUTTING APPARATUS 3 Sheets- Sheep 2Filed March 20, 1953 Nov. 12, 1957 H. HOFFMAN KEY CUTTING APPARATUS 5Sheets-Sheet 3 Y Filed March 20 1953 5 4 am 4 w L/w 4 J I 8 i I 2 W 5 f4 -0 19/ W M a United States Patent KEY CUTTING APPARATUS HaroldHoffman, Chicago, Ill. Application March 20, 1953, Serial No. 343,582Claims. (Cl. 164-50) This invention relates to key cutting apparatus andhas more particular reference to key cutting apparatus of the type usedby locksmiths for the notching of replacement keys for all automotivelocks.

In general it is the purpose of this invention to provide improved keynotching apparatus of the character described which featuresexceptionally simple means for presenting a key blank to notching meansoperating in a fixed cutting zone, to assure accurate spacing and depthof the notches to be cut.

More specifically it is the purpose of this invention to provide a keynotching appaartus of the character described wherein the means forpresenting the key blank to the cutting zone comprises a carriagemounted for swinging motion to and from an operative position about anaxis spaced from the cutting zone and adjustable along a path parallelto said axis, and a clamp structure for the key blankmounted on thecarriage for bodily motion therewith and for motion relative theretotoward and from the cutting zone along a path substantially normal tothe axis about which the carriage may swing. This enables the clampstructure to be swung with the carriage to a position spaced from thecutting zone to facilitate securement of a key blank in the clampstructure, and inspection of a partially notched blank or removal of acompletely notched key from the clamp structure.

In this connection it is another object of this invention to so mountthe carriage that it may be swung out of its operative position toenable inspection of apartly notched blank without disturbing the notchspace adjustment of the carriage.

It is a further object of this invention to provide a key notchingapparatus of the character described wherein the initial propulsion ofthe clamp structure toward the cutting zone to bring a key blank in theclamp structure into notching position effects locking of the carriageagainst swinging motion out of its operative position.

Still another object of this invention resides in the provision of a keynotching device of the character described wherein both the carriage andthe clamp structure are propelled back and forth along their respectivepaths at right angles to one another by screws having detachable manualcontrol knobs thereon bearing a plurality of matched sets of indicia,each knob being cooperable with a reference point to indicate the degreeof rotation of the knob and its screw necessary to set the carriage andclamp structure at the proper locations necessary to achieve accuratespacing and depth of the notches for any of a plurality of differenttypes of automotive keys. In this connection it is another object ofthis invention to provide a novel rotation transmitting connectionbetween each of the control knobs and its screw by which the controlknobs are readily interchangeable with others having different matchedsets of indicia thereon without danger of applying the control-knobs totheir screws in positions angularly misaligned with respect to theindicia thereon.

Still another object of this invention resides in the pro vision of anovel punch and die construction for key notching apparatus of thecharacter described, along with an improved method of making the punchand die.

With the above and other objects in view, which will appear as thedescription proceeds, this invention resides in the novel construction,combination and arrangement of parts substantially as hereinafterdescribed and more particularly defined by the appended claims, it beingunderstood that such changes in the precise embodiment of thehereinafter disclosed invention may be made as come within the scope ofthe claims.

The accompanying drawings illustrate one complete example of thephysical embodiment of the invention constructed acconding to the bestmode so far devised for the practical application of the principlesthereof, and in which:

Figure 1 is a perspective view of the key cutting apparatus of thisinvention.

Figure 2 is a side elevational view of the apparatus shown in Figure 1,with portions thereof broken away and shown in section;

Figure 3 is a sectional view taken through Figure 2 along the plane ofthe line 3-3;

Figure 4 is an enlarged fragmentary sectional view taken through Figure3 along the plane of the line 4-4;

Figure 5 is a group perspective view illustrating the manner in whichthe control knobs are connected with their screws to impart rotationthereto;

Figure 6 is an enlarged fragmentary cross sectional glow taken throughFigure 2 along the plane of the line 6; and

Figure 7 is an enlarged fragmentary cross sectional yiew taken throughFigure 2 along the plane of the line Referring now more particularly tothe accompanying drawings in which like reference characters designatelike parts throughout the several views, the numeral 5 generallydesignates the frame of the key cutting apparatus of this invention. Theframe comprises a substantially U-shaped base providing spacedsupporting legs 6, and a post 7 extending upwandly from the rear orbight end of the U-shaped base. At the front thereof immediately abovethe base the post is recessed as at 8 to provide space for a die block9. The die block seats upon a platform 10 extending forwardly from thebight end of the base flush with the upper edges of the legs 6 of thebase. The die block is secured to the platform on the base as by screws12 threaded upwardly into the die block from beneath the platform.

The portion of the post which overlies the die block is provided with avertical bore 14 communicating with a vertical slot 15 in the upper endof the post. This bore accommodates a key notching punch 17, and theslot 15 in the upper end of the post receives one end of a lever 18pivotally mounted on a pin 19 anchored in the upper end of the post andextending across the slot 15 to constrain the lever to pivotal motionabout a horizontal axis substantially directly over the bore 14.

The upper end of the punch is provided with a cylindrical cam follower20 loosely slidably and rotan'ly fitting the bore 14 and extending intothe slot 15 for cooperation with a cam surface 21 on the pivoted end ofthe lever 18. A leaf spring 22 carried by the upper end of the post ispreferably interposed between the upper end of the punch and the camsurface 21 to provide a good wearing surface along which the cam slidesduring downward and forward pivotal motion of the lever to cam the punchdownwardly in its cutting stroke into a hole 24 in the die block. Acompression spring 25 encircling the punch and confined between itscylindrical upper end portion 20 and the top of the die block yieldinglyresists dowm ward camming of the punch and at all times maintains theupper end of the punch in engagement with the cam surface 21 on theoperating lever 13.

The punch is provided with fiat forwardly converging sides 27 whichdefine a blunt edged nose 28 on the front portion of the punch by whichsubstantially flat bottomed V-shaped notches may be cut in one edge of akey blankbrought under the punch and partly over the hole 24 in the dieblock. During the notching operation, the edge of the blank to benotched is rested upon a supporting surface 29 on the die block definedby a cutout 30 therein opening to the front of the block. The hole 24 inthe die block, of course, has a shape corresponding to the cross sectionof the punch and when the latter is driven downwardly thereinto by theoperating lever 18, an exceptionally accurate cut or notch will be madein the edge of a key blank lying on the suporting surface 29 by reasonof the fact that the punch has an extremely close fit in the cavity, aswill be brought out later.

The two legs 6 of the base extend forwardly in spaced apart parallelrelationship and conjointly support a notch indexing shaft 32 at theirouter ends. The opposite ends of the shaft are reduced in diameter andare received in bushings 34 pressed into the legs to support the shaftfor rotation about a horizontal axis normal to the legs 6. The largerdiameter portion of the shaft lying between the legs is screw threadedand shoulders 35 at the opposite ends thereof bear against the adjacentends of the bushings 34 to preclude axial motion of the screw shaft 32relative to the base. One reduced end 36 of the shaft projects adistance beyond the outer side of its leg 6 to receive a manual controlknob 37 thereon by which an operator of the apparatus may impart backand forth rotation to the shaft.

Mounted on the notch indexing shaft 32 is a carriage 39 having athreaded aperture in its front portion in which the screw threadedintermediate portion of the shaft is received so that rotation of theshaft in opposite directions propels the carriage bodily lengthwise ofthe shaft back and forth between the two legs 6 of the base. The screwthreaded connection between the carriage and the shaft also provides fortilting motion of the carriage about the shaft axis between asubstantially horizontal operative position and an inoperative positionseen in construction lines in Figure 2. The horizontal, or operativeposition of the carriage is defined by the engagement of its rearwardlyextending, end portion 40 upon a ledge 41 on the base projectingforwardly from the platform thereon; and the weight of the rear portion40 of the carriage normally maintains the carriage in its horizontalposition regardless of the direction of rotation of the screw shaft 32to propel the carriage in one direction or the other.

A clamp structure, indicated generally by the numeral 42, is provided tohold a key blank in position to have notches cut in one edge thereof.This clamp structure is mounted upon the rear portion 46) of thecarriage for bodily motion therewith and for back and forth horizontalmotion relative to the carriage in a direction normal to the axis of thescrew shaft 32. For this purpose the rearwardly extending portion of thecarriage has a substantially flat top surface, upon which the body 43 ofthe clamp structure seats, and has a slot 44 therein opening to its rearextremity to slidably receive the upright stem 45 of a slide block 46 ofinverted T-shaped cross section. The slide block is secured to theunderside of the body 43 by a single screw 46' with the end of its stemreceived in a shallow slot 44' in the underside of the body to precludeswivelling of the slide block about the axis of the screw 46'. The head45 of the inverted T-shaped slide block engages under the rear portion49 of the carriage to hold the clamp structure from lifting off of thecarriage.

Accordingly, the clamp structure is constrained to reciprocatory motionrelative to the carriage toward and from the fixed cutting zone definedby the key notching means on the base, along a path normal to the axisof the screw shaft 32. Such back and forth motion of the clamp structurerelative to the carriage is essential not only to enable a key blanksecured in the clamp structure to be advanced rearwardly into thecutting zone, but to also enable the adjustment of the depth of thenotches to be cut in the edge of the key blank presented to the keynotching means.

The clamp structure is provided with'cooperating stationary and movablejaws 47 and 48, respectively, at its rear portion facing the die block.The stationary jaw 47 is on the body 43 of the clamp structure and isprovided by a substantially horizontal ridge on the rear of the bodyhaving its top surface lying in the plane of the supporting surface 29on the die block and parallel to the fiat supporting surface on thecarriage upon which the clamp structure slides.

The movable jaw 48 overlies the stationary jaw and is provided by adownwardly directed flange along the rear of a substantiallychannel-shaped clamp 49. A downwardly extending flange 50 at the frontof the clamp received in a shallow cross slot 51 in the body 43 providesa fulcrum about which the movable clamp is supported for limited pivotalmotion about an axis parallel to the axis of the screw shaft 32. Hence,the jaws 47 and 48 cooperate with one another to receive one edge of akey blank B to be notched, and the movable jaw is forced downwardly intoclamping relationship with an edge of the key blank between the jaws bymeans of a screw 53 passing loosely through the body of the clamp andthreading into a hole in the body 43 of the clamp structure. The screw53, of course, has a flange 54 which bears against the top of the clampto press the same downwardly as the screw is turned into its hole in thebody of the clamp structure. A compression spring 55 reacting betweenthe underside of the clamp and the body of the clamp structureyielding'ly urges the clamp upwardly to release a key blank from thejaws when the clamp screwis backed outwardly of its threaded hole.

The clamp structure has a screw threaded connection with the carriage bywhich it may be propelled back and forth relative tothe carriage towardand from the cutting zone to provide for adjustment of the depth of thenotches to be'cutin a key blank carried by the clamp structure. Thisscrew threaded connection comprises a bushing 57 fixed in the body 43and having a threaded hole normal to the axis of the screw shaft 32 andopening to the front of the body of the clamp structure. A second screwshaft 58 supported by the carriage but restrained against axial motionrelative thereto has its rear end portion threaded into the bushing 57.The screw shaft 58 has a reduced front end 59 freely rotatablyjournalled in;a hole in an upstanding portion 60 on the carriage, and itprojects forwardly through the portion 60 to receive a manual controlknob 61 on its front extremity.

The junction of the threaded portion of the screw shaft 58 with itsreduced front end portion 59 defines a shoulder 62 which engages therear of the upstanding portion 60 on the carriage to preclude forwardaxial motion of the shaft relative to the carriage; while a collar 67inside the inner end of the control knob 61 is secured to the forwardlyprojecting end of the shaft 58 and engages the front of theupstandingportion 60 to preclude rearward axial motion of the shaft with respectto the carriage. It will be apparent, therefore, that rotation of thescrew shaft 58 by its knob 61 will impart either forward or rearwardsliding motion to the clamp structure depending upon the direction inwhich the knob is rotated; 1

The upstanding portion 60 of the carriage also provides an abutmentwhichis engaged by the clamp structure to define the inoperativeposition thereof retracted from the cutting zone, and at which a keyblank held by the jaws 47 and 48 lies outside the cutting zone. In thisretracted position of the clamp structure the rear free edge of the keyblank B, in which notches are to be cut, may still rest on the extremeforward edge portion of the supporting surface 29, a slight distanceforwardly of the hole 24 therein. Consequently, rotation of the controlknob 61 in a counterclockwise direction as viewed in Figure 1 effectsrearward propulsion of the clamp structure, to the left as seen inFigure 4, to advance the key blank held in its jaws into the cuttingzone, or more particularly, bring its exposed rear edge over the hole 24so that a V-shaped notch can be cut in its rear edge at a location alongthe length of the blank determined by the notch indexing adjustment ofthe carriage under the control of the knob 37.

It is to be understood that the notches are cut in the rear edge of thekey blank successively starting from the extreme end of the blade asindicated in Figure 3, each time indexing the blank longitudinally byrotating the control knob 37 a predetermined angular distance in thesame direction, and each time adjusting for the desired notch depth byrotation of the control knob 61 predetermined angular distances in theproper direction.

As brought out hereinbefore, the carriage may be tilted out of itsoperative horizontal position shown in solid lines in Figure 2 to carrythe clamp structure upwardly and forwardly away from the cutting zone.In the tilted position seen in construction lines in Figure 2, a keyblank may be readily inserted into or removed from the jaws of the clampstructure, or a notch cut in the blank may be inspected withoutdisturbing the notch indexing adjustment of the carriage. This lastfeature results from the fact that there will always be sufiicientfriction in the screw threaded connection between the carriage and theshaft 32 that the latter will rotate with the carriage during tiltingthereof to and from its operative position.

Such tilting motion of the carriage is possible, however, only in theretracted or inoperative position of the clamp structure at which atongue 64 projecting rearwardly from the underside of the slide block 45clears the underside of the ledge 41 on the platform of the base.

As shown in Figure 4, the tongue 64 just clears the ledge 41 when theclamp structure is fully retracted, so that initial rearward propulsionof the clamp structure along the carriage to bring a key blank intocutting position effects engagement of the tongue under the ledge 41, asshown in construction lines, to preclude tilting motion of the carriageand the clamp structure thereon out of operative positions. In otherwords, tilting of the carriage is impossible whenever the clampstructure is in an operative position presenting a key blank to thenotching means, and the clamp structure must be retractedby itscontrol'knob 61 if for any reason it is desired to swing the carriageout of its horizontal position either for inspection of a notch cut inthe key blank or for removal of a completely notched blank from the jawsof the clamp structure.

Attention is directed to the fact that each of the control knobs 37 and61 has a novel detachable driving connection with its shaft fora purposenow to be described. Since these connections are identical, adescription of one will sutfice for both. Referring to Figure whichillustrates the knob 37 and the reduced end portion 36 of the screw 32,the inner end of the knob is provided with a counterbore 66 of adiameter and depth to receive a collar 67 fixed on the end portion 36 ofthe screw shaft and lying directly against the outer side of theadjacent leg 6 of the base. One or more set screws 68 threading radiallyinto the collar are provided to permanently secure the collar to theshaft.

The knob 37 is drivingly connected with the screw shaft 32 through thecollar 67 and for this purpose the collar and the knob are provided withmale and female driving elements which interengage with one another whenthe knob is properly angularly disposed on the reduced end portion ofthe shaft to provide a rotation transmitting connection between the knoband the shaft. The driving elements, in the present case, comprise aneccentric pin 69 on the collar projecting forwardly from the outer facethereof parallel to the axis of the screw shaft and slidingly but snuglyreceived in a hole 70 in the knob opening to the bottom of itscounterbore 66.

One or more set screws 71 may be provided to detachably hold the knob onthe reduced extremity of the shaft but it should be understood thatthese set screws have no other function, the knob being locatedangularly on the shaft solely by the cooperating male: and femaledriving elements 69 and 70.

As indicated in Figuresl and 5, a plurality of circumferential bands 72,73 and 74 are delineated on each of the knobs, one band for each ofthree different types of automotive keys which may be notched by theapparatus of this invention. Each band, of course, is marked with thename of the particular type of lock or automobile upon which the lock isused. For example, the circumferential bands 72 at the inner ends ofboth knobs may be calibrated for the keys of all General Motorsautomobiles; the bands 73 calibrated for the keys of all Chryslerautomobiles; and the bands 74 calibrated for the automotive keys markedBriggs and Stratton.

Suitable indicia, such as the lines and numerals indicated, aredelineated on the sets of bands on the two knobs to facilitate theadjustment of the carriage and the clamp structure. Thus, the indicia onany one band on the knob 37, when aligned with a fixed reference point76 on the base will readily enable an operator of the apparatus to indexthe carriage to the proper position along the screw shaft 32 for thecutting of any one of the notches in a key blank secured in the clampstructure; while the indicia on the corresponding or matching band onthe knob 61, when aligned with a fixed reference point 77 on thecairiage enables the clamp structure to be adjusted towardand from thekey notching means to secure the desired depth for the notch to be cut.

The fixed reference point 76 on the base may be a line delineated upon aplate of clear plastic 78 secured to the upper edge of the leg 6 tooverlie the knob 37, the line lying in a vertical plane containing theaxis of the screw shaft 32. Preferably the plastic plate is disposed asclose as possible to the periphery of the knob 37 so as to minimize thepossibility of errors in the alignment of any of the indicia on thevarious bands thereof with the reference line 76.

The fixed point 77 is also preferably a line delineated on a clearplastic plate 79 secured to the top of the upstanding portion 60 of thecarriage, and this line also lies in a vertical plane containing theaxis of the screw shaft 58 and closely overlies the periphery of theknob 61.

When notching a General Motors key for instance, the indicia on bothbands 72 of the two knobs are employed throughout the entire notchingoperation, the indicia on the knob 37 corresponding to positions of thenotches lengthwise of the key blank and the indicia on the knob 61corresponding to the various depths of the notches to be cut. It isunderstood, of course, that locksmiths employing the key notchingapparatus of this invention will ordinarily be provided with codes ordecoding apparatus to enable any particular key of the different typesmentioned to be notched on the apparatus.

Since there are several more types of keys for automotive locks than thethree types mentioned, this invention makes it possible to readilyconvert the apparatus for the notching of such different types of keysmerely by the substitution of a different set of matched control knobsfor the knobs 37 and 61 described. Any number. of such matched sets ofknobs can be provided to take care of future needs as new types ofautomotive locks are put on the market.

When changing knobs, it will be understood that the inter-engagement ofthe male and female driving ele-.

ments 69 and 70 automatically locates the knobs angularly on theirrespective shafts. Consequently, since the holes 70 in the bottoms ofthe knob counterbores can be accurately located angularly with respectto the indicia thereon by the manufacturer of the apparatus, thelocksmiths in changing from one set of matched knobs to another cannotfail to secure the knobs on their shafts in the proper angular positionthereon.

All notch spacing and depth adjustments afforded by the matched sets ofcontrol knobs, of course, are predicated upon accurate location of theblanks to be notched in the jaws of the clamp structure. For thispurpose the side of the body 43 adjacent to the knob 37 may itselfprovide a stop engageable by an abutment on certain types of key blanksto locate those blanks lengthwise of the jaws.

Other gage means must be provided for the other types of keys having alocating abutment on the opposite edge of the key blank which ispresented to the notching means. In the present case this gage meanscomprises a lever 81 normally received in a slot 82 in the body 43 ofthe clamp structure opening to the top thereof near its side adjacent tothe control knob 37. The rear of the lever is pivoted on a pin 83carried by the body 43 so that its front end may be swung rearwardly,about a horizontal axis parallel to the axis of the screw shaft 32 overthe blade of a key blank in the jaws. A locating finger 84 on the freeend of the lever is adapted to extend over the exposed edge of the keyblank in the jaws for engagement with the stop abutment on the blank toenable the same to be properly located lengthwise of the jaws.

The lever 81 is yieldingly biased to a retracted position received inthe slot 82 by means of a torsion spring 85 having one end fixed to ascrew 86 in the body and its other end fixed to the pin 83 upon whichthe gage lever is mounted, it being understood that the lever is fixedto the pin in any suitable manner.

In all cases, the key blank is secured in the jaws with the forwardlyfacing edge of the blank against the rear face of the body 43 to assurethat the blank will be parallel to the carriage screw 32.

Referring again to the punch and die, it is important to note that theseelements of the key notching apparatus of this invention are not onlynovel in construction but that they are made by a new and novel methodwhich assures the utmost accuracy in notching key blanks, substantiallywithout producing burrs as the result of the notching operation.

As stated previously, the die block has a notch 01 slot 30 opening toits front which has the effect of dividing the block into an upper punchguiding portion 88 and a lower notching portion 89 containing the hole24. The hole in the guide portion 88 of the die block, of course, ismade to very accurately fit the shank of the punch so that the punch isguided for vertical motion primarily by its sliding fit therein, ratherthan in the bore of the post above the die block as was the practiceheretofore. Also due to the non-circular cross sectional shape of thepunch and the hole in the guide portion of the block, the punch is heldagainst rotational movements thereby eliminating the troublesome andcostly practice heretofore resorted to in accurately keying the punch inthe bore of the post and locating the die block with respect to the borein the post.

According to the present invention, the punch is merely loosely guidedin the bore 14 of the upright post of the apparatus, and is not inanywise restrained against rotation thereby. Additional guidance as wellas rigidity is afforded the punch by reason of the fact that it has atail portion 91 at its rear projecting downwardly from its cutting face92 and at all times engaging in the hole 24 to bear against the rearedge thereof. Thus, during the downward cutting stroke of the punch anytendency for the punch to be cammed rearwardly, due' to the slant of itscutting face, is precluded by the tail piece 91.

The punch and die are also made by a unique method which involves firstshaping and grinding of the punch to the desired configuration shown,after which the punch is hardened. The die block before hardeningthereof, is notched at one side thereof to define the spaced upper andlower flanges on the block. Thereafter the flanges are broached toprovide aligning punch receiving holes therein which substantiallycorrespond to the crosssectional shape of the punch. The holes areaccurately machined along their cylindrical rear portions to fit thecylindrical rear portion of the punch, but at their front edge portions,the holes are made slightly undersize, about .030".

After the holes have been made in the manner described, the finished andhardened punch is driven downwardly through both holes in the die blockto actually shear away the softer metal of the block along theconverging front edges of the holes, to thus assure that the hole in theupper guide flange of the block and the lower hole 24 will veryaccurately fit the punch. This assures against the possibility oflateral or rotational movements of 'the punch in the die, andpractically eliminates the formation of burrs on the key blanks notchedthereby.

During the shearing operation described, of course, the downwardlyextending tail along the rear of the punch enters both holes in the dieblock in advance of the cutting face of the punch, with the result thatthe punch cannot cam itself rearwardly away from the sloping front edgesof the holes as it cuts through the die block. After the die block hasbeen punched out in the manner described and hardened, it is secured tothe platform on the base while the punch is in position within the bore14 and with its lower end received in both holes of the die block. Thismaterially simplifies proper location of the die block on the base; andit will be seen that the punch and the die cooperate to provide a unitwhich is more or less independent positionally of the punch actuatingmeans on the base.

From the foregoing description taken together with the accompanyingdrawings it will be readily apparent to those skilled in the art thatthis invention provides an improved key notching apparatus featuring apivotally mounted carriage which is automatically locked againstswinging motion in consequence of initial propulsion of the clampstructure rearwardly toward the notching means; that it features asimple but unique manner of providing for proper indexing and notchdepth adjustment through the provision of interchangeable matchedcontrol knobs for the screw shafts by which such adjustments areeffected; and provides a punch and die of improved construction whereinthe punch is guided solely by the die block and the punch and die aremade by a new and improved method which assures greatest accuracy of thenotching operations substantially without burr.

What I claim as my invention is:

1. In a key notching device: an elongated base; means near the rear endof the base defining a cutting zone fixed with respect to the base; acarriage extending horizontally rearwardly along the base toward saidcutting zone; a horizontal screw threaded connection between the frontportions of the carriage and the base providing for swinging of the rearportion of the carriage upwardly and forwardly away from the cuttingzone about the axis of said screw threaded connection, said screwthreaded connection providing for propulsion of the carriage in oppositedirections along a path parallel to said axis; means on the baseengageable by the carriage to define said horizontal position thereof; aclamp mounted on the rear portion of the carriage for bodily motiontherewith and for back and forth motion relative thereto lengthwise ofthe base, toward and from the cutting zone; a screw threaded connectionbetween the carriage and the clamp providing for propulsion of the clamptoward and from the cutting zone; and cooperating means on the carriageand the base brought into interengaging relationship in consequence ofpropulsion of the clamp to a position adjacent to the cutting zone topreclude swingin'g motion of the carriage out of its horizontalposition.

2. In a key notching device; a base having means thereon defining acutting zone fixed with respect to the base; a carriage supported on thebase in a substantially horizontal position and having front and rearportions, the rear portion of the carriage being disposed adjacent tothe cutting zone; a clampmounted on the rear portion of the carriage forrecip'rocatory motion relative to the carriage toward and from thecutting zone; cooperating stops on the clamp and the carriage forlimiting motion of the clamp away from the cutting zone to define theretracted position of the clamp '21 which a key blank held hereby isspaced from the cutting zone; a screw threaded connection between thefront portion of the carriage and the base by which the carriage may bepropelled in opposite directions along a path normal to the path ofreciprocatory movement of the clamp to impart notch indexing motion tothe clam said connection providing for swinging of the rear portion ofthe carriage and the clamp thereon upwardly and forwardly away from thecutting zone to a position facilitating insertion of a key blank intothe clamp; and cooperating means on the carriage and the baseinterengageable with one another in the horizontal position of thecarriage whenever the clamp is moved from its retracted position to aposition adjacent to the cutting zone, for holding the carriage againstswinging motion out of its horizontal position.

3. In a key notching device having a base and key notching means on thebase defining a cutting zone fixed with respect to the base, theimprovement thereof which comprises: a carriage supported on the basefor tilting motion toward and from a substantially horiozntal operativeposition about an axis spaced from said cutting zone, and for back andforth motion along a path parallel to said axis, said carriage having aportion extending from its axis toward the cutting zone; a clampengageable with one edge of a key blank for presenting the opposite edgeof the blank to said notching means; means mounting the clamp on saidportion of the carriage for bodily motion relative thereto along a pathnormal to the pivot axis of the carriage so that the clamp may be movedtoward and from the cutting zone in the horizontal position of thecarriage to provide for adjustment of the depth of notches to be cut ina key blank in the clamp; manually operable means on the base connectedwith the carriage for driving the same back and forth along said pathparallel to its pivot axis to thereby impart notch indexing motion tothe clamp; manually operable means on the carriage connected with theclamp for driving the clamp toward and from the cutting zone; andcooperating means on the clamp and the base interengageable with oneanother in the horizontal position of the carriage as a consequence ofmovement of the clamp toward the cutting zone a distance to bring a keyblank in the clamp into cutting position, for precluding tilting of thecarriage out of its horizontal position.

4. In a key notching device of the type having a base, a clamp movablealong a defined path toward and from a fixed cutting zone on the base toprovide for adjustment of the depth of notches to be cut in a key blanksecured in the clamp, and a carriage for carrying the clamp back andforth along another defined path normal to said first designated path toimpart notch indexing motion to the clamp: manually controlled means onthe base connected with the carriage for driving the same and the clampthereon back and forth along said other path; manually controlled meanson the carriage connected with said clamp for propelling the same backand forth relative to the carriage along said first designated path;means esteem i l0 mounting the carria e on the base for tilting motionout of an operative position about an axis spaced from the cutting zoneand parallel to said other path to enable the clamp to be swung with thecarriage to a position a distance away from the cutting zone and atwhich a key blank may be readily secured in or removed from the clamp;and cooperating means on the clamp and the base interengageable with oneanother upon movement of the clamp along said first designated path to aposition adjacent said cutting zone to preclude such tilting motion ofthe carriage whenever the clamp is in an operative position presentingakey blank to the cutting zone.

5. The key notching device set forth in claim 4 wherein the means fortiltably mounting the carriage on the base and for propelling the sameback and forth along said other path comprises a screw shaft rotatablyjournalled on the base and having the carriage threaded thereon.

p 6. The key notching device set forth in claim 4 wherein saidcooperating means on the clamp and the base comprises a ledge on thebase and a tongue on the clamp engageable under said ledge upon movementof the clamp to a position adjacent to the cutting zone to precludetilting of the carriage whenever the clamp is in an operative positionpresenting a key blank to the cutting zone.

7. The key notching device set forth in claim 4 wherein the carriage hasa slot therein substantially normal to its pivot axis, and the clamp hasa slide block thereon received in said slot to constrain the clamp toreciprocatory motion on the carriage, toward and from the cutting zone;and further characterized by the fact that said cooperating means whichinterengage in the operative position of the clamp to preclude swingingof the carriage on its axis includes a tongue on the slide blockprojecting therefrom toward the cutting zone.

8. The key notching device set forth in claim 4 wherein the means formounting the carriage for swinging motion and for moving the same backand forth along said other path comprises a screw shaft rotatablycarried by the base and passing through a threaded hole in the carriage;and wherein the base is provided with a ledge spaced from said screwshaft and upon which the carriage rests in the operative positionthereof so that the carriage is jointly supported by the screw shaft andsaid ledge; and further characterized by the fact that the clamp isprovided with a tongue to engage under said ledge upon movement of theclamp to a position adjacent to the cutting zone to preclude tilting ofthe carriage out of its operative position whenever a key blank ispresented to the cutting zone by the clamp.

9. The key notching device set forth in claim 10 Wherein each knob has acounterbore therein, and wherein said cooperating male and femaledriving elements on each screw and its knob comprises a collar fixed 0nthe screw and received in the counterbore of the knob, said collarhaving a pin thereon eccentric to but parallel with the screw axis andprojecting into a hole in the bottom of the counterbore in the knob todrivingly connect the knob with the screw.

10. In a key notching device of the type having a base, a clamp movablealong a defined path toward and from a fixed cutting zone on the base toprovide for adjustment of the depth of notches to be cut in a key blanksecured in the clamp, and a carriage for the clamp movable back andforth along another path normal to the first designated path to impartnotch indexing motion to the clamp: means for shifting the carriage backand forth along said other path, including a carriage transporting screwconstrained to rotation in the base and threaded into the carriage;means for propelling the clamp back and forth along said firstdesignated path including a clamp transporting screw constrained torotation in the carriage and threaded into the clamp; detachablemanually operable matching control knobs on said screws by which thescrews may be rotated in 11 opposite directions to effect notch spacingand depth adjustment, said notches having sets of indicia delineated ontheir surfaces in circumferentially adjacent bands, the bands of indiciaon the knob for the carriage transporting screw representing diiferentspacings for the notches to be cut in different types of key blanks, andthe indicia of each band thereof on the knob for the clamp transportingscrew representing notch depths to be used With one of the notch spacingbands on the knob for the carriage transporting screw; a pair oftransparent plates, one fixed on the base directly over the surface ofthe knob for the carriage transporting screw and the other fixed on thecarriage directly over the surface of the knob for the clamptransporting screw 50 that the indicia on said knobs is readily visiblethrough the plates from above, each of said plates having a singlereference line delineated thereon, said lines lying in vertical platescontaining the axes of rotation of their respective knobs and beingcooperable with the indicia on the knobs to indicate the rotationaladjustments of the screws necessary for the cutting of notches of theproper spacing and depth in different types of key blanks; and meansdrivpredetermined relationship with respect to their driving elements.

References Cited in the file of this patent UNITED STATES PATENTS1,452,308 .Miller Apr. 17, 1923 1,615,020 Loehr et al. Jan. 18, 19271,678,319 Blessing July 24, 1928 2,051,139 Griflith Aug. 18, 19362,058,719 Pigman Oct. 27, 1936 2,317,527 Herb Apr. 27, 1943 2,323,949Vosburg July 13, 1943 2,619,853 Lange Dec. 2, 1952

